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A261010 Write 5^n in base 3, add up the "digits". 2
1, 3, 5, 7, 7, 9, 9, 13, 15, 13, 13, 17, 19, 21, 21, 27, 25, 25, 25, 23, 27, 33, 31, 39, 35, 45, 37, 57, 45, 47, 45, 45, 53, 47, 55, 51, 57, 59, 67, 67, 69, 65, 67, 65, 71, 79, 71, 65, 67, 75, 65, 71, 73, 83, 69, 79, 81, 85, 79, 89, 87, 95, 89, 85, 97, 99, 93, 101, 107 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Chai Wah Wu, Table of n, a(n) for n = 0..10000

Cernenoks J., Iraids J., Opmanis M., Opmanis R., Podnieks K., Integer complexity: experimental and analytical results II, arXiv:1409.0446 [math.NT] (September 2014)

K. Podnieks, Digits of pi: limits to the seeming randomness, arXiv:1411.3911 [math.NT], 2014.

MAPLE

S:=n->add(i, i in convert(5^n, base, 3)); [seq(S(n), n=0..100)];

PROG

(Python)

def digits(n, b=10): # digits of n in base 2 <= b <= 62

    x, y = n, ''

    while x >= b:

        x, r = divmod(x, b)

        y += str(r) if r < 10 else (chr(r+87) if r < 36 else chr(r+29))

    y += str(x) if x < 10 else (chr(x+87) if x < 36 else chr(x+29))

    return y[::-1]

def A261010(n):

    return sum([int(d) for d in digits(5**n, 3)]) # Chai Wah Wu, Aug 14 2015

CROSSREFS

Sum of digits of k^n in base b for various pairs (k,b): A001370 (2,10), A011754 (3,2), A261009 (2,3), A261010 (5,3).

Sequence in context: A103470 A316852 A307120 * A064002 A195868 A228543

Adjacent sequences:  A261007 A261008 A261009 * A261011 A261012 A261013

KEYWORD

nonn,base

AUTHOR

N. J. A. Sloane, Aug 14 2015

STATUS

approved

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Last modified July 16 11:09 EDT 2020. Contains 335784 sequences. (Running on oeis4.)